The Wedge-rumped Storm Petrel has separate breeding populations in the Galápagos and off South America. It lives at sea, and the populations differ in some features.
Adults are dark, with a deeply forked tail and a large white rump patch. The Peru-Chile coastal population is described as smaller, with a deeper tail fork and a reduced white patch than the Galápagos population.
Outside the breeding period it lives over open water; the account describes post-breeding movement toward waters influenced by the Humboldt Current. It nests in island cliffs and crevices in lava or stonework.
An extinction-risk assessment has not been added yet.